* Turkish police block migrants from reaching EU frontier
* Turn back 200 migrants from Bulgaria border after tip-off (Updates with Bulgarian police comment)
By Humeyra Pamuk
EDIRNE, Turkey, Sept 16 (Reuters) - Hundreds of mostly Syrian migrants spent the night out in the open near Turkey's border with Greece after Turkish police halted their attempt to reach the frontier and cross into the European Union.
Piles of rubbish and makeshift tents had sprung up along the roadside by Wednesday morning near the city of Edirne, 17 km (11 miles) by road from the border crossing. Police, some in riot gear, prevented the migrants continuing their journey.
Security forces had on Tuesday briefly thrown up barricades to halt the progress of hundreds trying to reach EU-member Greece, and buses from Istanbul to Edirne were halted.
Bulgarian border police said they had prevented around 200 people reaching the Bulgarian-Turkish border early on Wednesday.
"The Bulgarian border police officers received a signal that groups of migrants were walking up to the border," spokeswoman Lora Lyubenova told Reuters. "They immediately informed their Turkish colleagues, who took appropriate measures and did not allow the groups to reach the border."
After spending a cold night under the stars and with daytime temperatures expected to soar, some families headed back to Istanbul, but many would-be migrants insisted they would seek a way to cross the border at any cost.
"I am young, I am strong. If I can make it to Europe perhaps I can have a life. We have degrees, we have education, there's nothing for us here in Turkey," said 25-year-old Saleh, an electronics engineer from the Syrian city of Aleppo.
Turkey is sheltering more than 2 million Syrians and Iraqis, the largest refugee population in the world. But a lack of jobs and hopes of a better life in Europe have led an ever-growing number to attempt crossings into neighbouring countries.
With Ankara struggling to manage the humanitarian fallout and frustrated at what it sees as lack of support from European partners, there are fears officials could begin turning a blind eye to those trying to leave Turkey.
Turkish President Tayyip Erdogan again put the blame for the refugee crisis on his one-time ally and now bitter foe, Syrian President Bashar al-Assad.
"We cannot bear any longer to sit back and watch bodies of children and women washed ashore on the coasts of the Mediterranean and Aegean as a result of a forced helplessness," he said in a speech in Ankara. "The solution of this crisis is through bringing down the tyrannical regime in Syria."
Erdogan told German Chancellor Angela Merkel on the phone on Wednesday that the Turkish coastguard had rescued more than 50,000 refugees in the Mediterranean this year, a number higher than the sum of those rescued in the past five years.
Merkel said she appreciated Turkey's work on the refugee crisis and added that Germany was expecting the number of refugees it hosts to reach 800,000 by the end of the year, a transcript of the call from the Turkish president's office said.
The leaders agreed that a political solution was essential to end the civil war in Syria. Erdogan reminded Merkel of Turkey's demand for an Islamic State-free zone in northern Syria and noted that it expected a more active stance from the international community for a solution of the conflict.
Migrants have in recent days turned to Turkey's land borders due to spiralling death tolls on sea routes to Europe.
On Tuesday a further 22 people drowned when their overcrowded boat capsized. (Additional reporting by Ece Toksabay and Angel Krasimirov in Sofia; Writing by Jonny Hogg; Editing by David Dolan and Mark Heinrich)
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